A friend of mine sent me a link to this site which makes printable templates for just about everything. Tube notching, tube miters, tube through sheet, protractors, circle dividers, degree wheels, cones, scale rulers, it even will print customized graph paper. It looks like there's something useful for building just about any plane. This is the circle divider, the other types of templates are links at the top of the page. https://www.blocklayer.com/circle-divider.aspx Hope this helps someone!